Causes Of Cancer

Question 1

Cancer often only appears after a sequence of…

Answer 1

Separate events.

Many different types of cancer, caused by different factors

Question 2

Genetic factors:

Answer 2

Some people have proto-oncogenes which are more likely to mutate than others
Why some types or cancer are more common in some families than others - e.g. breast cancer, BRCA1 and BRCA2 that increase the chances a person will get breast cancer

Question 3

Age: older you are more likely you are to suffer from cancer, partly because they have had…

Answer 3

More years of exposure to environmental factors (ionising radiation and carcinogens)
Also because they are older they have had the chance to accumulate damage to their DNA

Question 4

Ionising radiation: this includes X rays, alpha and beta radiation

Answer 4

Contains a great deal or energy so penetrates bonds in DNA molecules

Question 5

Ultraviolet radiation: has less ionising radiation, but does ave enough energy to penetrate skin cells (sunburn)
It breaks…

Answer 5

Bonds in the DNA of skin cells and can cause skin cancer

Question 6

Chemicals: many chemicals can cause cancer, these are called…

Answer 6

Carcinogens
Cigarette smoke contains several different carcinogens
Asbestos fibres, some pesticides and diesel exhaust can also cause cancer

Question 7

Viruses:

Answer 7

Best-known one is human papilloma virus, some kinds can cause cervical cancer.
Types of the HPV carry the code for a protein that interfere with a tumour-suppressor gene
HPV is passed on through sexual inter course